This issue aims to add an enhancement to the SOL/INSOL (mode setup 11) design.
The SOL/INSOL enhancement we are including in this issue is to add a tunable parameter for the redistribution of aerosol into its 4 main species within the hygroscopicity routine. Aerosol grows due to its hygroscopicity and if we treat all aerosol as sulphate, we see a much faster growth than if we treat it as it the different species we know it is, as organic/black carbon aerosol is more hydrophobic and grow slower. This isn't an issue over certain domains where sulphate is the dominant species but over the Amazon domain, for example, we see AOD grow significantly within even one hour from initialisation. This fix will include adding a namelist item, and so will need a link to a UM issue and PR, and will allow users to tune the ratio of aerosol species, allowing for improved aerosol growth in areas where sulphate isn't dominant. It will only have an impact on when mode setup 11 is applied.
This issue is linked to MetOffice/um#58
This issue aims to add an enhancement to the SOL/INSOL (mode setup 11) design.
The SOL/INSOL enhancement we are including in this issue is to add a tunable parameter for the redistribution of aerosol into its 4 main species within the hygroscopicity routine. Aerosol grows due to its hygroscopicity and if we treat all aerosol as sulphate, we see a much faster growth than if we treat it as it the different species we know it is, as organic/black carbon aerosol is more hydrophobic and grow slower. This isn't an issue over certain domains where sulphate is the dominant species but over the Amazon domain, for example, we see AOD grow significantly within even one hour from initialisation. This fix will include adding a namelist item, and so will need a link to a UM issue and PR, and will allow users to tune the ratio of aerosol species, allowing for improved aerosol growth in areas where sulphate isn't dominant. It will only have an impact on when mode setup 11 is applied.
This issue is linked to MetOffice/um#58